Infection due to contact with unsanitary medical equipment has long posed a danger to personnel handling such equipment. Contact with used medical needles is particularly hazardous since needles are characteristically very sharp objects which can cause accidental wounds.
Previous attempts to provide safety sheaths have concentrated on preserving sterility of a packaged needle prior to use and on protecting the user against injury while fastening the sterile needle to a syringe. Examples of such structures can be found in U.S. Pat. No. 2,953,243 issued to Roehr for DISPOSABLE NEEDLE ASSEMBLY; U.S. Pat. No. 3,074,542 issued to Myerson for PACKAGE FOR HYPODERMIC NEEDLES; U.S. Pat. No. 3,294,231 issued to Vanderbeck for DENTAL NEEDLE SHIELD; U.S. Pat. No. 3,367,488 issued to Hamilton for HYPODERMIC SYRINGE PACKAGE; and U.S. Pat. No. 3,329,146 issued to Waldman for NEEDLE CONTAINER. Although some of the structures disclosed in these references may also be used for disconnecting a used needle from a syringe for disposal, particularly Roehr '243, Vanderbeck '231 and Waldman '146, none of the structures disclosed provides adequate protection against injury to the hand of the user holding the sheath during reinsertion of a used needle.
Other previous attempts to provide needle sheaths which ensure sterility and provide protection against injury while fastening the needle to a syringe involve structures which must be partially destroyed to access the sterile needle. Examples of such structures, which do not provide any protection against injury or infection during disposal of the used, unsanitary needle, are found in U.S. Pat. No. 3,073,307 issued to Stevens for NEEDLE HUB AND SHEATH STRUCTURE; U.S. Pat. No. 3,333,682 issued to Burke for DISPOSABLE NEEDLE CONTAINER; and U.S. Pat. No. 3,934,722 issued to Goldberg for STERILE NEEDLE PACKAGE.
Infection even without direct contact with a used hypodermic needle also can be caused by atmospheric migration of bacteria. While some previous attempts have provided a sheath which may be used to disengage a used needle from a syringe, no structure has been provided which prevents bacteria migration. Examples of structures which allow bacteria migration after disposal of the used needle are found in U.S. Pat. No. 4,133,090 issued to Carstens for MEDICAL INSTRUMENT PACKAGE and Hamilton '488.
The only attempts to provide adequate protection against injury from direct contact with used hypodermic needles during disposal involve cannister-type containers. One such device utilizes sharp blades to sever a used needle from a syringe after it is inserted into an aperture in the cannister. Such a cannister suffers from several disadvantages. First, a cannister with blades is cumbersome and involves inconvenient transportation of the cannister itself or dangerous transportation of an exposed, used needle to the cannister. Second, the configuration of the cannister so as to contain many used needles necessarily involves a possibility that an infected needle may assume a position piercing the cannister, thereby exposing personnel handling the cannister to dangers of injury and infection by direct contact. Third, the requirement for an open aperture for inserting used needles permits undesirable bacteria migration which can also cause infection. Migration of bacteria can actually be increased by a "spray" of bacteria occurring as the sharp blades sever the infected needle.
An improved cannister for used needle disposal is disclosed in U.S. Pat. No. 4,375,849 issued to Hanifl for SYRINGE NEEDLE REMOVAL AND DISPOSAL DEVICE. This patent discloses rim guards extending from the lid of the cannister over the user's hand providing protection during insertion of a used needle, a lid opening configured for disengaging the used needle from a syringe without blades, and a closable lid to retain used needles. However, this structure also suffers from several disadvantages overcome by the present invention. While the Hanifl '849 device is described as portable, carrying the cannister to an appropriate treatment station is inconvienient since it involves handling an additional piece of equipment. Moreover, since many needles are to be disposed of in a single cannister, carrying the cannister involves risk of injury from a previously inserted needle protruding through the cannister wall. If the Hanifl '849 device is accidentally upset with the lid in the open position, i.e., while in a position to receive additional needles, previously inserted, unsanitary needles may fall out of the cannister. Reinserting such spilled needles involves direct contact with the exposed needles, thereby increasing the risk of injury. Finally, the Hanifl lid must be reopened each time another used needle is inserted, allowing potentially infectious bacteria to migrate from previously inserted needles. This last disadvantage is aggravated by the portable nature of the device since the cannister will most likely be opened in the presence of patients being treated, exposing all involved to the danger of infection from bacteria migration.
It is therefore an object of this invention to provide a new and improved safety sheath for needles.
A further object of this invention is to provide a new and improved needle safety sheath which permits control over a needle without direct contact, particularly during removal from and insertion into the sheath.
A still further object of this invention is to provide, in a new and improved needle safety sheath, means for retaining a needle in the sheath.
A still further object of this invention is to provide a new and improved needle safety sheath which permits a used needle inserted therein to be disconnected from a syringe without direct contact and which does not permit the needle to become dislodged after such disconnection from a syringe.
Another object of this invention is to provide a new and improved needle safety sheath which protects the user from injuries due to needle contact during insertion of a needle into the sheath.
A still further object of this invention is to provide, in a new and improved needle safety sheath, means for guiding a needle into a sheath sleeve during insertion.
Another object of the present invention is to provide a new and improved needle safety sheath which prevents migration of bacteria from an unsanitary needle contained therein.
Another object of the present invention is to provide a new and improved needle safety sheath which does not permit access to an unsanitary needle contained therein.
A further object of the present invention is to provide a new and improved needle safety sheath package which is tamper-proof prior to use and which does not allow access to an unsanitary needle after use.
These and other highly desirable and unusual results are accomplished by the present invention in an economical structure which may be disposed of with confidence that no injury or infection from the unsanitary needle will result.
Objects and advantages of the invention are set forth in part herein and in part will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.
The invention consists in the novel parts, constructions, arrangements, combinations, steps, and improvements herein shown and described.